1-[5-(Anthracen-9-yl)-3-(4-nitro-phen-yl)-4,5-dihydro-1H-pyrazol-1-yl]ethan-1-one.

In the title compound, C(25)H(19)N(3)O(3), steric repulsion between the methine H atom and one of the anthryl H atoms seems to be concomitant with the considerable distortion of the anthryl fragment from planarity. The side rings of the anthryl subtend an angle of 9.57 (8)°, which is an extreme value among the known reliably determined structures. This angle correlates with the length of the bond by which the anthryl is attached to the rest of the mol-ecule. In the anthryl fragment, the maximum deviation of one of the C atoms from the mean plane is 0.126 (3) Å and regards the carrier C atom involved in the repulsion between the anthryl and the methine H atoms. The inter-planar angle between the pyrazoline ring and the anthryl fragment is 88.36 (5)° and that between the pyrazoline and 4-nitro-phenyl rings is 8.80 (15)°. Weak inter-molecular C-H⋯N, C-H⋯π and π-π inter-actions [centroid-centroid distances of 3.7659 (17), 3.9477 (15) and 3.8972 (15) Å] are pesent in the structure.